1. Field of the Invention (Technical Field)
The invention relates to a paracentesis valve operable solely by hydraulic force; and a method for using such valve.
2. Background Art
The medical procedure known as paracentesis is tedious and potentially dangerous. The procedure normally entails insertion of a syringe or trocar into a body cavity, for example the thoracic or abdominal cavities and subsequent fluid removal or drainage from such cavity.
Paracentesis procedures in the past normally required a manually operated three-way valve. Moving the valve lever in a predetermined direction enabled withdrawal of fluid into a syringe barrel; moving the lever in another direction enabled voiding and expulsion of fluid from the syringe barrel into a receptacle. The disadvantages of this procedure include patient discomfort, improper valve manipulation, valve jamming, and the risk of torn gloves and subsequent infection.
The following U.S. patents are exemplary of the prior art valves and procedure: U.S. Pat. No. 4,844,087 to Garg, entitled First Method for Using Cannula Including a Valve Structure and Associated Instrument Element; U.S. Pat. No. 4,447,235 to Clarke, entitled Thoracentesis Device; U.S. Pat. No. 4,784,156 to Garg, entitled Cannula Including a Valve Structure and Associated Instrument Elements and Method for Using Same; U.S. Pat. No. 4,840,184 to Garg, entitled Second Method for Using Cannula Including a Valve Structure and Associated Instrument Elements; and U.S. Pat. No. 4,832,044 to Garg, entitled Cannula Including a Valve Structure and Associated Instrument Elements.
U.S. Pat. No. 3,957,052, to Topham, entitled Pumping-Syringe, discloses a T-passageway valve configuration for withdrawing and pumping fluids. Ball check valves are used. Similarly, U.S. Pat. No. 4,051,852, to Villari, entitled Aspirating Device, discloses ball, flap and cylindrical check valve member embodiments for withdrawing body fluids and thereafter pumping them into suitable collection bags. U.S. Pat. No. 657,440 to McCaw, entitled Aspirator, discloses similar structure.
U.S. Pat. No. 3,515,163 to Freeman, entitled Respiratory Apparatus does disclose a respiratory valve with a sliding valve member. The sliding valve member, however, is magnetically biased, and flow occurs through centrally located orifices in the sliding valve member. U.S. Pat. No. 3,877,616, to Stevens, entitled Pump With Unitary Valve Member, discloses a reciprocating valve member with upper and lower resilient check valves. U.S. Pat. No. 4,592,382, to Rubin, et al., entitled Anti-Siphon Nozzle, discloses an unbiased slidable valve member.
U.S. Pat. No. 4,246,932, to Raines, entitled Multiple Additive Valve Assembly; and U.S. Pat. No. 4,729,401, to Raines, entitled Aspiration Assembly Having Dual Co-Axial Check Valves, both disclose pumping devices for medical fluids employing resilient disk check valves. U.S. Pat. No. 2,567,391 to Mead, entitled Exhaust Valve Structure also discloses a resilient valve member.
It is seen that none of the above references disclose a biased slidable valve member operable solely by hydraulic force to first withdraw fluid from the patient, then allow such fluid to be automatically voided into a receptacle.